WO2011118646A1 - Robot hand and robot device - Google Patents

Abstract

Disclosed is a robot hand and a robot device that can readily achieve flexible gripping of a target gripping object, wherein the flexible gripping follows the shape of said target object. The robot hand is an underactuated robot hand (8) with a greater number of joints than actuators and comprises a palm section (11); three finger sections (12) whereby the bases thereof are connected to the palm section (11) and which comprise a plurality of links (16, 17, and 18) connected in a manner that enables bending; and a shape-fitting mechanism (US) positioned on one finger section (12A) which enables grasping such that a target gripping object (9) is enclosed by the finger sections (12) through the application of torsional displacement to the links (16, 17, and 18) .

Description

Robot hand and robot device

The embodiment of the disclosure relates to a robot hand and a robot apparatus including articulated fingers for gripping an object.

In recent years, development of robots that can work on behalf of humans is expected. This robot hand needs to be able to handle tools used by humans. As prior art relating to such a robot hand, for example, those described in Patent Documents 1 to 3 are already known.

In the prior art described in Patent Document 1, in a multi-finger multi-joint robot hand, a configuration in which a shape memory metal is inserted between adjacent movable fingers and a finger-to-finger contact portion of the shape memory metal is pulled and driven by a moving pulley is disclosed. Has been.

In the prior art described in Patent Document 2, in a robot hand in which the first link, the second link, and the third link are connected, it is expanded and contracted by applying a voltage in a state of being connected between the first link and the second link. A configuration in which a polymer actuator for driving the first link is provided is disclosed.

The prior art described in Patent Document 3 discloses a configuration in which a plurality of links provided on the index finger and the ring finger are rotated inward and outward using a worm gear, a worm wheel, and a motor.

Japanese Patent Laying-Open No. 2009-83020 (page 13, FIG. 1) Japanese Patent Laying-Open No. 2005-46980 (page 4, FIG. 1) Japanese Patent Laid-Open No. 2008-149448 (page 17, FIG. 1)

However, in the conventional techniques described in Patent Document 1 and Patent Document 2, the bending direction of each finger at each joint is limited, and thus the degree of freedom in the gripping operation is low. As a result, it is difficult to perform more flexible gripping, for example, following the shape of the gripping object. The internal rotation / exversion function of the prior art described in Patent Document 3 is merely to move a plurality of fingers in the opening / closing directions by rotating the link in a plane, and it follows the shape of the object to be grasped. There was a limit to the flexible gripping. In any case, in the above-described prior art, flexible gripping following the shape of the object cannot be easily realized.

An object of the present invention is to provide a robot hand and a robot apparatus that can easily realize flexible gripping according to the shape of the target object.

In order to solve the above-described problems, according to one aspect of the present invention, there is provided a robot hand of an underactuated mechanism having a number of joints greater than the number of actuators, wherein the palm is connected to the base and bent. At least two fingers having a plurality of links connected to each other and at least one of the fingers, which is necessary for imparting torsional displacement to the links and driving the joints A robot hand having a conforming mechanism that enables gripping so as to wrap a gripping object with the finger by performing at least one of the adjustments of the driving torque is applied.

According to the present invention, it is possible to easily realize flexible gripping according to the shape of the target object.

1 is a conceptual explanatory diagram of a robot apparatus including a robot hand according to a first embodiment. It is a perspective view showing the appearance structure of the robot hand concerning a 1st embodiment. It is a longitudinal cross-sectional view which shows the internal structure of the whole finger | toe part provided with a twist joint part. It is a perspective view of the external appearance of the twist mechanism with which a twist joint part is equipped. It is a perspective view of a finger part provided with three bending joints and one twist joint part. It is a model figure of 4 joint fingers of a finger part provided with a twist joint part. It is a front view of the guide plate of the twist mechanism in the modification which obtains a restoring force with a tension spring. It is a principal part expansion longitudinal cross-sectional view of the 1st link in the modification which obtains a restoring force with a permanent magnet. FIG. 10 is a front view of a twist mechanism and a side cross-sectional view taken along a section IX-IX in FIG. 9A in a modified example in which a restoring force is obtained by a rubber member. It is a perspective view showing the external appearance structure of the robot hand which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the whole internal structure of a finger part provided with an inferior drive mechanism. It is the schematic showing an example of the structure of the stopper in the state which the link extended. It is a schematic diagram showing an example of composition of a stopper in the state where a link bent. It is the schematic showing an example of a structure of a torsion spring. It is a longitudinal cross-sectional view which shows the internal structure of the whole finger | toe part in the modification which arrange | positions a 2nd motor in a link. It is a longitudinal cross-sectional view which shows the internal structure of the whole finger | toe part in the modification which arrange | positions a 2nd motor in a link using a worm gear. It is the schematic showing an example of the modification using a tension spring. It is a perspective view showing the external appearance structure of the robot hand in the modification which has the finger part which consists of two links. It is a longitudinal cross-sectional view which shows the whole internal structure of the finger part which consists of two links. It is a longitudinal cross-sectional view which shows the internal structure in the other structural example of the finger part which consists of two links. It is a figure for demonstrating operation | movement of the finger part in the other structural example of the finger part which consists of two links. It is a top view showing the external appearance structure of the robot hand in the modification which makes the structure which can perform the internal rotation / external rotation operation | movement of a finger | toe part. It is a sectional side view which shows the detail of the palm part of the robot hand in the modification which enables the internal rotation / external rotation operation of a finger part. It is a sectional side view which shows the schematic structure inside the finger | toe part of a robot hand in the modification which enables the internal rotation / external rotation operation of a finger | toe part. It is a top view which shows the state which hold | gripped the big holding | grip target object with the robot hand in the modification made into the structure which can perform the internal rotation / external rotation operation | movement of a finger | toe part. It is a side view which shows the state which hold | gripped the big holding | grip target object with the robot hand in the modification which enables the internal rotation / external rotation operation | movement of a finger | toe part. It is a top view which shows the state which hold | gripped the small holding | grip target object with the robot hand in the modification which enables the internal rotation / external rotation operation | movement of a finger | toe part. It is a side view which shows the state which hold | gripped the small holding | grip target object with the robot hand in the modification made into the structure which can perform the internal rotation / external rotation operation | movement of a finger part. It is a sectional side view which shows the structure which has arrange | positioned the motor in the back part in the modification which enables the internal rotation / external rotation operation | movement of a finger | toe part. It is a sectional side view of the planetary gear mechanism with which the finger part of the robot hand concerning a 3rd embodiment was provided. It is a sectional side view of the whole finger part of the robot hand concerning a 3rd embodiment. It is explanatory drawing for demonstrating the operation principle of the finger | toe part which concerns on 3rd Embodiment. It is a sectional side view of the planetary gear mechanism of the modification which performs torque transmission using a pulley. It is a figure showing the structure of the joint restraint mechanism which restrains a joint by restraining a shaft. It is a figure showing the structure of the joint restraint mechanism which restrains a joint by restraining a shaft using a shape memory alloy. It is the horizontal sectional view and side sectional view of a wave gear mechanism in a modification using a wave gear mechanism as a torque transmission mechanism. It is a sectional side view of the wave gear mechanism of the modification which performs torque transmission using a pulley.

<First Embodiment>
First, the first embodiment will be described. In the present embodiment, it is possible to grip the object to be gripped with a finger by a conforming mechanism that imparts torsional displacement to the link.

1, the robot apparatus 1 has a robot body 2 and a personal computer 3 (hereinafter abbreviated as PC3) that controls the operation of the robot body 2. The PC 3 corresponds to an example of a controller described in the claims. The controller may be provided on the robot body 2 side, for example, near each joint of the robot body 2 or in the palm 11 of the robot hand 8.

The robot body 2 in the illustrated example is a two-joint arm type robot, and includes a first joint actuator 4 fixed to the floor, a first arm 5 whose position and orientation is controlled by the first joint actuator 4, According to the present embodiment, the second joint actuator 6 fixed to the tip of one arm 5, the second arm 7 whose position and orientation is controlled by the second joint actuator 6, and the second arm 7 fixed to the tip of the second arm 7 The robot hand 8 is provided.

In the above configuration, the robot body 2 can bring the robot hand 8 closer to the grasped object 9 by controlling the position and orientation of the corresponding arms 5 and 7 by the joint actuators 4 and 6, respectively. The robot hand 8 grips the gripping object 9, and further controls the position and orientation of the arms 5 and 7, whereby the gripping object 9 can be moved. In the example shown in the figure, the robot hand 8 is moved only by the rotational movements of the two joint actuators 4 and 6. In addition to this, the arms 5 and 7 are caused to perform the rotational movement with the longitudinal direction as the rotational axis. An actuator (not shown) or the like may be provided, and the robot is not limited to two joints and may be a multi-joint (for example, seven joints) robot.

The PC 3 generates and transmits control commands corresponding to the actuators 4 and 6 included in the robot body 2, thereby controlling the actuators 4 and 6 in a coordinated manner and gripping and controlling the robot hand 8. Is controlled to operate smoothly.

In FIG. 2, the robot hand 8 of the illustrated example has a palm part 11 and three finger parts 12 that are connected to the palm part 11 and have roots extending from the palm part 11. . Each finger portion 12 has three links 16, 17, and 18 connected in series via two second joints 14 and third joints 15 each formed of a hinge, and further has one link 16 on the root side. It is connected to the palm 11 through the first joint 13. In this example, the rotation axes of the joints 13, 14, 15 in one finger portion 12 are in a parallel arrangement relationship, and each finger portion 12 can bend and extend so as to swing on one plane. ing. By bending the three fingers 12 so as to be close to each other, the robot hand 8 can grip the object 9 to be gripped with three-point support. As a feature of the robot hand 8 of the present embodiment, at least one of the three finger portions 12 (in this example, the finger portion 12A located at the upper right in FIG. 2) is at least one link (this In the example, a twist joint 19 is provided on the link 16) that is directly connected to the palm 11.

Next, the entire internal structure of the finger portion 12A including the twist joint portion 19 described above will be described with reference to FIG. In addition, in FIG. 3, about the wall part etc. which comprise the outer shell of the palm part 11 and each link 16, 17, 18 which are hollow structures, illustration is abbreviate | omitted suitably.

3, the first link 16 is connected to the edge of the palm 11 via a first joint shaft 21 so as to be bent. A second link 17 is bendably connected to the free end of the first link 16 via a second joint shaft 22, and a second joint 17 is connected to the free end of the second link 17 via a third joint shaft 23. Three links 18 are connected so as to be bendable. In a normal state, the rotation axes of the three joint shafts 16, 17, 18 are arranged in parallel with each other.

The palm 11 is provided with a first joint drive motor 24, and a first joint drive gear 26 fixed to the output shaft of the first joint drive motor 24 is fixed to the first joint shaft 21. It meshes with the first joint driven gear 27. The first joint shaft 21 is rotatably supported with respect to the palm portion 11, and is fixedly coupled to the first link 16. Thereby, the first link 16 can be actively bent with respect to the palm portion 11 by the rotational drive of the first joint drive motor 24. The first joint drive motor 24 corresponds to an example of the actuator and the first actuator described in each claim.

The second joint drive motor 25 is installed on the first link 16, and the second joint drive gear 30 is fixed to the output shaft of the second joint drive motor 25. The second joint shaft 22 is rotatably supported with respect to the first link 16, and is also rotatably supported with respect to the second link 17 by a bearing 28A. The second joint drive gear 30 meshes with a second joint driven gear 31 fixed with respect to the second joint shaft 22. Thereby, the second link 17 can be actively bent with respect to the first link 16 by the rotational drive of the second joint drive motor 25. The second joint drive motor 25 corresponds to an example of the actuator and the second actuator described in each claim.

A third joint drive pulley 32 is integrally coupled to the second joint driven gear 31. On the other hand, a third joint driven pulley 33 is fixed to the third joint shaft 23, and a belt 34 is stretched between the third joint driven pulley 33 and the third joint driving pulley 32. A wire member may be used. The third joint shaft 23 is rotatably supported by the bearing 28 </ b> B with respect to the second link 17, and is fixedly coupled to the third link 18. As a result, the rotation drive of the second joint drive motor 25 is transmitted via the belt 34, whereby the third link 18 can be actively bent with respect to the second link 17. Further, since the belt 34 is simply stretched between the two pulleys 32 and 33 (not twisted), the second joint drive motor 25 is driven to rotate both the second link 17 and the third link 18. It bends toward the same side during In other words, the third link 18 bends in an under-driven manner of the second link 17. The bending angle of the third link 18 is also affected by the pulley diameter ratio between the third joint driving pulley 32 and the third joint driven pulley 33.

And the said 1st link 16 is divided | segmented into two of the 1st small link 35 and the 2nd small link 36 along the axial direction. The tip portion of the first small link 35 located on the palm 11 side is fitted and inserted into the second small link 36 located on the fingertip side (second link 17 side). Although not particularly illustrated, for example, the fitting portion of the first small link 35 is formed in a cylindrical shape, and the fitting portion of the second small link 36 is formed with an inner diameter that is substantially the same as the outer periphery of the cylindrical portion. Yes. For this reason, the first small link 35 and the second small link 36 are connected to each other around a rotation axis along the longitudinal direction of the entire first link 16 so as to be capable of relative torsional displacement. A joint portion 19 is configured (see portion A in FIG. 2). In addition, a small link bearing 37 is provided between the outer periphery of the first small link 35 and the inner periphery of the second small link 36, and the small link bearing 37 is connected to the first small link 35 and the second small link in the radial direction. The sliding between the links 36 is made smooth and the slipping between the first small links 35 and the second small links 36 is prevented in the thrust direction. The second joint drive motor 25 is installed inside the second small link 36. The first small link 35 and the second small link 36 correspond to an example of two small link members described in each claim.

Furthermore, a twist mechanism 38 for assisting relative torsional displacement between the first small link 35 and the second small link 36 is provided inside the twist joint portion 19 of the first link 16. The detailed structure of the twist mechanism 38 will be described with reference to FIG.

4 and FIG. 3, the twist mechanism 38 includes a shaft support plate 41, a shaft 42, a guide plate 43, a shaft bearing 44, two guide rods 45, and a torsion spring 46. . The shaft support plate 41 and the guide plate 43 are each formed in a disk shape having substantially the same diameter, and are arranged in parallel so that their center axes coincide with each other. The shaft 42 is formed in a hollow cylindrical shape, one end (the lower end in FIG. 3) is fixed to the center of the shaft support plate 41, and the other end (the upper end in FIG. 3) penetrates the center of the guide plate 43. A shaft bearing 44 is rotatably supported.

The guide plate 43 is formed with two arc-shaped guide grooves 47 having the same inner peripheral angle with respect to the center thereof. Each of the two guide rods 45 has one end (lower end in FIG. 3) vertically coupled to the shaft support plate 41, and the other end (upper end in FIG. 3) penetrates the corresponding guide groove 47. Yes. The guide rod 45 and the guide groove 47 have the same arrangement relationship in each combination. For example, when the guide rod 45 is located at the end of one guide groove 47 as shown in the drawing, the other guide groove 47 also corresponds. The guide rod 45 comes to be located at the end. As a result, the shaft support plate 41, the shaft 42, and the two guide rods 45 are connected to the guide plate 43 so as to be relatively rotatable by the inner peripheral angle of each guide groove 47.

The torsion spring 46 is a helically wound spring, and is coaxially disposed on the outer periphery of the shaft 42, one end (lower end in FIG. 3) is fixed to the shaft support plate 41, and the other end (in FIG. 3). Is fixed to the guide plate 43. Thereby, the guide plate 43 is always urged from the shaft support plate 41 in the same rotation direction (counterclockwise direction in the example shown in FIG. 4).

The shaft 42 corresponds to an example of a shaft member described in each claim, and the shaft bearing 44 corresponds to an example of a bearing member. The side walls of the guide rods 45 and 45 and the guide grooves 47 and 47 correspond to an example of a guide member, and the groove ends of the guide grooves 47 and 47 correspond to an example of a regulating member. The torsion spring 46 corresponds to an example of a first spring member and an example of a restoring force applying member.

The twist mechanism 38 having such a configuration is disposed so as to penetrate the fitting portion of the first small link 35 and the second small link 36 (that is, the twist joint portion 19) and the rotation axis. Specifically, the shaft support plate 41 is fixed inside the first small link 35, and the guide plate 43 is fixed inside the second small link 36. Further, the shaft 42 is formed with a through hole 48 extending therethrough in the axial direction, and the cable member 49 of the second joint drive motor 25 is passed through the through hole 48. The shaft 42 is provided on the first small link 35, while the shaft bearing 44 is provided on the second small link 36 to support the shaft 42 rotatably. Further, the two guide rods 45 and the two guide grooves 47 guide the relative rotation of the first small link 35 and the second small link 36 accompanying the rotation of the shaft 42 and the first small link 35 accompanying the rotation of the shaft 42. The amount of rotation of the link 35 and the second small link 36 in the relative rotation direction is limited within a predetermined range. Further, the torsion spring 46 rotates in the forward rotation direction (the guide plate 43 of the second small link 36 in the counterclockwise direction in FIG. 4 and the shaft support plate 41 of the first small link 35 in the clockwise direction as the shaft 42 rotates). A restoring force is applied to displace the first small link 35 and the second small link 36 that are displaced in the direction away from each other in the direction opposite to the above.

Thus, in the present embodiment, the finger portion 12A is provided with the conforming mechanism US having the first small link 35 and the second small link 36, the twist joint portion 19, and the twist mechanism 38, and the second link 17 and the third link. By applying torsional displacement 18, the gripping object 9 can be gripped by the three finger portions 12.

In FIG. 5, the axial center line of the third joint shaft 23 between the third link 18 and the second link 17, and the axial center line of the second joint shaft 22 between the second link 17 and the first link 16. These are driven by the second joint drive motor 25 disposed inside the second small link 36 so as to bend each other. In other words, the bending joints of the first joint shaft 21, the second joint shaft 22, and the third joint shaft 23 each having only one degree of freedom have the links 16, 17, 18 on the same plane even if they are combined. It has only a degree of freedom to swing (bend / extend). On the other hand, in the finger portion 12A provided in the present embodiment, the first link 16 is provided with the twist joint portion 19, and the first small link 35 and the second small link 36 as shown in FIG. Since rotation (relative torsional displacement) is possible, the degree of freedom of movement of the fingertip can be further increased.

For example, in the posture of FIG. 5, when an external force F is applied to a point B located on the belly of the finger of the third link 18, the distance from the external force F to the rotation axis CL of the second small link 36 is the rotation radius R, A torque T is generated around the rotation axis of the second small link 36. The biasing force of the torsion spring 46 of the twist mechanism 38 acts so as to resist the torque T, and the second small link 36 and the first small link 35 are in a stationary state at a predetermined angle. As long as the external force F is not applied, the twist mechanism 38 is attached to the extent that the relative angle between the third link 18, the second link 17, the second small link 36, and the first small link 35 is maintained at zero. Power is needed. That is, the torsion spring 46 needs to have a spring rigidity that can hold the weights of the third link 18, the second link 17, and the second small link 36 in a state where no object is gripped.

Next, using the model diagram of the four joint fingers shown in FIG. 6, the motion equation of the finger part 12A of the robot hand 8 is obtained and the behavior is analyzed.

6, the twist joint portion 19 is constrained by a torsion spring 46 around the Z axis, and is disposed between the first small link 35 and the second small link 36. The twist joint 19, the first small link 35, and the second small link 36 correspond to the first link 16. A second joint 14, a second link 17, a third joint 15, and a third link 18 are disposed at the free end of the first link 16, and the first link 16 is driven by the first joint 13. The axial center point of the first joint 13 is the origin, the length from the first joint 13 to the twist joint portion 19 is l0, the length from the first joint 13 to the second joint 14 is l1, and the second joint 14 to the second The length to 3 joints 15 is set to l2. At this time, for example, RM. Murray, ZLi, S.M. Based on “A mathematical introduction to Robotic Manipulation” by S Sasty (CRC press, 1994, p172 to p175), the equation of motion is obtained as follows. First, when the twist vectors (ξ1, ξ2, ξ3, ξ4) of the points on the joints 13, 14, 15 are obtained, the following equation (1) is obtained. The twist vector is obtained from the velocity vector and the angular velocity vector.

When the relative positions of the mass centers of the links 16, 17, 18 are obtained with the axis center point of the first joint 13 as the origin, the mass center position of the first small link 35 between the first joint 13 and the twist joint 19 ( 0, 0, r ₀ ), the mass center position (0, 0, l ₀ + r ₁ ) of the second small link 36 between the twist joint 19 and the second joint 14, and the second joint 14 and the third joint 15. When the mass center position (0, r ₂ , l ₁ ) of the second link 17 between them and the mass center position (0, l ₂ + r ₃ , l ₁ ) of the third link 18 are assumed, and the angular velocity is 0, the following formula (2)

Next, the Jacobian matrix of position and orientation is expressed by the following equation (3).

Here, s _i represents sin (θ _i ), c _i represents cos (θ _i ), s _ij represents sin (θ _i + θ _j ), c _ij represents cos (θ _i + θ _j ), and I _ii represents Represents moment of inertia. J ₄₁₁ , J ₄₁₂ , J ₄₂₁ , and J ₄₃₁ are omitted because the expressions are complicated. Since M _i ^* calculates the inertia tensor for the coordinate system with the center of gravity of each link as the origin, the off-diagonal term is zero. Further, by using the Lagrangian method or the like, the following formula (4) is finally obtained.

In this equation, c _ij represents a centrifugal force or Coriolis force, N represents a gravity term, K ₂ represents a torsion spring constant of the twist joint 19, K ₃ represents a torsion spring constant of the second joint 14, and K ₄ represents a first value. The torsion spring constant of the three joints 15 is represented. Further, since the torque of each actuator is two variables τ ₁ and τ ₂ as shown in the equation (4), it is simpler than the case where each joint 13, 14, 15 is driven.

Next, the actual control content of the finger part 12A of the robot hand 8 in accordance with the principle represented by the equation of motion will be specifically described. As described above, the actuator that drives the first joint 13 is the first joint drive motor 24. The first joint drive motor 24 includes a controller (not shown) that outputs a motor current. This controller inputs a deviation signal between the first joint command calculated by the PC 3 based on the above equation of motion and angle information by an encoder (not shown) of the motor 24 and outputs a corresponding motor current. Then, the first joint drive motor 24 is driven. The driving force of the first joint drive motor 24 corresponds to the actuator torque τ1 of the equation (4), and the bending operation at the first joint 13 is controlled. The actuator torque τ1 corresponds to an example of the first driving force described in each claim.

Further, the actuator that drives the second joint 14 is the second joint drive motor 25 and the gears 30 and 31, and the actuator that drives the third joint 15 is the second joint drive motor 25. Similarly to the above, the controller (not shown) provided in the second joint drive motor 25 sends the second joint command calculated by the PC 3 and angle information by the encoder (not shown) of the second joint drive motor 25. The deviation signal is input, and the corresponding motor current is input to drive the second joint drive motor 25. The driving force of the second joint drive motor 25 corresponds to the actuator torque τ2 of the equation (4), and the bending operation at the second joint 14 and the third joint 15 is controlled. The actuator torque τ2 corresponds to an example of the second driving force described in each claim.

That is, the second joint drive gear 30 fixed to the output shaft of the second joint drive motor 25 drives the second joint driven gear 31 fixed to the second joint shaft 22. That is, the second joint drive motor 25 transmits the actuator torque τ 2 to the second link 17 via the second joint drive gear 30 and the second joint driven gear 31, and the second link around the second joint shaft 22. 17 is bent. The second joint drive gear 30 and the second joint driven gear 31 correspond to an example of a gear mechanism described in each claim and also an example of a second link drive transmission mechanism.

The second joint drive gear 30 fixed to the output shaft of the second joint drive motor 25 drives the second joint driven gear 31 fixed to the second joint shaft 22, and further, the third joint drive pulley 32 and the belt. 34 is driven, and the force is transmitted to the third joint driven pulley 33 fixed to the third joint shaft 23. That is, the second joint drive motor 25 also supplies the actuator torque τ 2 via the second joint drive gear 30, the second joint driven gear 31, the third joint drive pulley 32, the belt 34, and the third joint driven pulley 33. The third link 18 is transmitted to the third link 18, and the third link 18 is bent around the third joint shaft 23. The third joint driving pulley 32, the third joint driven pulley 33, and the belt 34 correspond to an example of the pulley mechanism described in each claim, and the second joint driving gear 30 and the second joint driven gear. 31 corresponds to an example of a third link drive transmission mechanism described in each claim.

As described above, in the present embodiment, at least one link 16 of any one finger portion 12A among the plurality of finger portions 12 and 12A included in the robot hand 8 is replaced with two small links 35 and 36. The structure is formed by dividing and connecting these two small links 35 and 36. These two small links 35 and 36 are capable of relative torsional displacement with respect to each other around the axis CL of the finger portion 12A. As a result, the finger portion 12A having the divided link 16 has one more degree of freedom due to the torsional displacement, so that the gripping direction approaching the gripping object 9 and the release away from the target object 9 as described above. In addition to being able to move in a direction, it is possible to change the angle toward the object 9 and change the facing posture of the object 9. By including at least one finger portion 12A provided with the conforming mechanism US that enables such movement, the robot hand 8 of the present embodiment can form a shape of the object 9 with respect to the object 9 rather than the conventional structure. It is possible to perform flexible gripping following the above. In addition, by providing a separate actuator, for example, approaching / separating at an angle according to the curved surface shape of the surface of the object 9, moving along the surface of the object 9, or obliquely with respect to the object 9 It is also possible to move closer and away with the posture being twisted.

In this embodiment, in particular, the relative rotation of the two small links 35 and 36 accompanying the rotation of the shaft 42 of the twist mechanism 38 is guided by the guide rod 45 and the guide groove 47 of the guide plate 43. Thereby, the small link 35 on one side and the small link 36 on the other side can be relatively displaced relatively, and a smoother movement of the finger portion 12A provided with the two small links 35 and 36 can be realized. it can.

In this embodiment, in particular, the amount of rotation in the relative rotation direction of the two small links 35 and 36 accompanying the rotation of the shaft 42 is limited within a predetermined range by the guide groove 47 of the twist mechanism 38. As a result, the relative displacement between the small link 35 on one side and the small link 36 on the other side can be kept within a certain range so that an unreasonable posture or an unnatural operation is not performed. As a result, smoother movement can be realized, and durability and reliability can be improved.

In this embodiment, in particular, the torsion spring 46 of the twist mechanism 38 provides a restoring force that displaces the two small links 35 and 36 that are displaced in the forward rotation direction in accordance with the rotation of the shaft 42 in the reverse rotation direction. Thereby, after the two small links 35 and 36 are relatively displaced and come into contact with the surface of the object 9, it is possible to realize a passive and stable gripping operation in accordance with the shape of the object 9. In addition, the passive operation increases the contact area with the object 9 between the third link 18 at the fingertip and the first link 16 at the root, and stable gripping can also be performed. Further, when the grasped object 9 is released, it can be naturally returned to the original state before the relative displacement without applying a forcible driving force in the return direction. As a result, it is possible to reliably realize a motion that is close to a human finger and has a little uncomfortable feeling.

In the present embodiment, in particular, the first link 16 on the palm portion 11 side is composed of two small links 35 and 36 that can be displaced relative to each other, and can perform a great posture change from the base side of the finger portion 12A. it can. In addition, the first link 16 is swung (bent and extended) by the actuator torque τ1 from the first joint drive motor 24 disposed in the palm portion 11, while the second link 17 and the third link 18 are changed to the first link. Oscillating (bending and extending) is performed by the actuator torque τ 2 of the two-joint drive motor 25 arranged. Thereby, the 1st link 16, and the 2nd link 17 and the 3rd link 18 can be made to rock | fluctuate (bend extension) mutually independently.

Further, the second joint drive motor 25 is arranged on the second small link 36 on the second link 17 side, and the actuator torque τ2 from the second joint drive motor 25 is obtained by the second joint drive gear 30 and the second joint driven gear. While being transmitted to the second link 17 by 31, it is also transmitted to the third link 18 by the third joint driving pulley 32, the belt 34 and the third joint driven pulley 33. By sharing the actuator for oscillating the second link 17 and the actuator for oscillating the third link 18, it is possible to reduce the load of the actuator drive control compared to the case where each actuator is driven by an independent actuator, and at a higher speed. Can swing (bend and extend). At this time, the third joint drive gear 30, the third joint driven gear 31, the third joint drive pulley 32, the belt 34, and the third joint driven pulley 33 receive the actuator torque τ 2 from the second joint drive motor 25. It can be transmitted to the third link 18. As a result, the third link 18 can be smoothly driven in the inferior driving mode of the second link 17, and a natural bending action similar to that of a human in conjunction with the bending action of the second link 17 can be realized. it can.

Furthermore, as described above, the actuator for driving the second link 17 and the third link 18 is shared by one second joint drive motor 25, and the first joint drive for driving the first link 16 is used. By disposing the motor 24 on the palm portion 11, only one actuator of the second joint drive motor 25 is disposed on the finger portion 12 </ b> A. As a result, the weight of the entire finger portion 12A can be reduced.

In this embodiment, the shaft 42 is provided with the through-hole 48 for allowing the cable member 49 to the second joint drive motor 25 to pass therethrough, so that the shaft 42 is disposed in the second small link 36 on the second link 17 side. The cable member 49 of the second joint drive motor 25 can be smoothly arranged on the palm portion 11 without being exposed to the outside of the robot hand 8. In addition, this makes it possible to arrange the power amplifier of the actuator on the palm portion 11, which can also reduce the weight of the finger portion 12 </ b> A.

In the above-described embodiment, a configuration in which relative torsional displacement can be performed only on the first link 16 in one finger portion 12A of the three finger portions 12 and 12A included in the robot hand 8 is provided. Not limited. For example, a plurality (or all) of the finger portions 12 may be provided, or the links 17 and 18 other than the first link 16 may be provided.

In addition, it is not restricted to the said embodiment, A various deformation | transformation is possible within the range which does not deviate from the meaning and technical idea. Hereinafter, such modifications will be described in order.

(1-1) In the case where a tension spring is used In the above embodiment, the return force for displacing the twist mechanism 38 in the direction opposite to the relative torsional displacement between the second small link 36 and the first small link 35 is twisted. Although obtained with the spring 46, it is not restricted to this. For example, the return force may be obtained by a tension spring that spans between the guide plate 43 and the guide rod 45.

In FIG. 7, the twist mechanism 38A of the present modification does not include the torsion spring 46 in the above embodiment, but includes two helical springs 51 instead. These two helical springs 51 are respectively stretched between the end of the corresponding guide bar 45 on the fingertip side (front side in the figure) and the end of the guide groove 47 which is the initial position. A biasing force is applied to pull the guide rod 45 toward each end. The helical spring 51 corresponds to an example of a spring member described in each claim and also corresponds to an example of a restoring force applying member.

Also in this modified example, it is possible to perform passive stable gripping operation and return to the original state after releasing the grip by using the urging force due to the elasticity of the helical spring 51, which is the same as in the above embodiment. An effect can be obtained.

(1-2) Using a permanent magnet In addition, a return force in the twist mechanism may be obtained using a permanent magnet. In FIG. 8, the twist mechanism 38B of the present modification does not include the torsion spring 46 in the above embodiment, but instead, the permanent magnet 52 is provided on each surface of the shaft support plate 41 and the guide plate 43 facing each other. Is provided. At that time, in a state where the shaft support plate 41 and the guide plate 43 are in the initial relative rotational position, the magnetic poles (N poles) of the permanent magnets 52 so that the pair of permanent magnets 52 facing each other exert an attractive force. And S pole) are arranged.

Thereby, since the opposing permanent magnets 52 are a combination of the N pole and the S pole or the S pole and the N pole, the shaft support plate 41 and the guide plate 43 are always returned to the initial positions. Giving the power to do. In this example, the shaft 42B and the guide rod 45B are formed relatively short so that the permanent magnets 52 facing each other can sufficiently influence each other, and the shaft support plate 41 and the guide plate 43 are sufficiently close to each other. Is arranged. Moreover, it is preferable to use, for example, aluminum or the like, which is a nonmagnetic material and has a low density, for each member of the shaft support plate 41, the shaft 42B, the guide plate 43, and the guide rod 45B constituting the twist mechanism 38B. The permanent magnet 52 corresponds to an example of the restoring force applying member described in each claim.

In this modification, a passive stable gripping operation or return to the original state after the grip release can be performed by using the attractive force that the pair of permanent magnets 52 and 52 attract each other. The same effect can be obtained. In addition, by using a non-contact method using magnetic force, it is possible to reliably prevent deterioration or deterioration of durability due to fatigue or aging, and replacement of parts becomes unnecessary.

(1-3) In the case of using a rubber member The return force may be obtained using a rubber member. 9A and 9B, the twist mechanism 38C of this modification includes a shaft support plate 41, a shaft 42, a rubber member storage body 53, a connecting member 54, and two pressing members 55. Two rubber members 56 are provided. The shaft support plate 41 and the shaft 42 are formed and fixed in the same manner as in the above embodiment. The entire rubber member housing 53 is formed in a cylindrical shape having substantially the same diameter as the shaft support plate 41, and the shaft 42 is rotatably supported through the center of the rubber member housing 53.

The rubber member housing 53 is formed with two arc-shaped deep grooves 57 having the same inner peripheral angle with respect to the axial center, and the deep grooves 57 have substantially the same arc shape in the axial direction. A long rubber member 56 is accommodated. The rubber member 56 and the deep groove 57 are provided with a gap between corresponding end portions in each combination, and a flat plate-shaped pressing member 55 is inserted into each of the gaps. The end portions of each pressing member 55 on the fingertip side (the front side in FIG. 9A and the right side in FIG. 9B) protrude from the end portion of the rubber member housing 53, respectively. It is being fixed to the free end of shaft 42 via. When the twist mechanism 38C of this modification is provided inside the first link 16, the shaft support plate 41 (together with the shaft 42 and the pressing member 55) is fixed to the first small link 35, and the rubber member storage body 53 is fixed to the second small link 36. The rubber member 56 corresponds to an example of the restoring force applying member described in each claim.

When the connecting member 54 and the two pressing members 55 together with the shaft 42 are rotated around the rotation axis of the shaft 42, the two pressing members 55 respectively press and compress the rubber members 56 in the rotation direction in the deep grooves 57. At this time, an urging force that causes the restoring force of each rubber member 53 to be displaced in the opposite rotation direction is applied to each pressing member 55, the connecting member 54, the shaft 42, and the shaft support plate 41. Each rubber member 56 that has been pressed and compressed is elastically deformed so as to extend along the direction of the rotation axis as indicated by the broken line in FIG. 9B. The amount of elastic deformation is the Poisson's ratio of the material of the rubber member 56. Determined by

As described above, in this modified example, the restoring force after elastic deformation of the rubber member 56 can be used to perform passive stable gripping operation or return to the original state after gripping release. The same effects as in the above embodiment can be obtained. Further, since the rubber member 56 has not only elasticity but also viscosity, the rubber member 56 can perform a certain degree of guide function and rotation amount regulation function with respect to relative rotation of the two small links 35 and 36. In this case, the guide rod 45 and the guide groove 47 in the above embodiment can be omitted. The rubber member 56 may be replaced with a resin member that can be similarly elastically deformed.

Second Embodiment
Next, a second embodiment will be described. In the present embodiment, an auxiliary torque is applied by a spring member so that the object can be gripped so as to be wrapped in any posture.

Since the configurations of the robot apparatus 1 and the robot body 2 including the robot hand 108 according to the present embodiment are the same as those in the first embodiment (FIG. 1), the description thereof is omitted.

In FIG. 10, the robot hand 108 has a palm part 111 and three finger parts 112 having roots connected to the palm part 111. Each finger part 112 has three links 116, 117, 118 connected in series via two second joints 114 and third joints 115 each formed of a hinge, and further, the link 116 on the root side is the first link 116. It is connected with the joint 113, and each finger part 112 can bend and extend so as to swing on one plane. By bending the three fingers 112 so as to be close to each other, the robot hand 108 can hold the object 9 with the three links 116, 117, 118 and the belly of the three fingers 112. The robot hand 108 according to the present embodiment includes an under-drive mechanism that interlocks and drives two adjacent joints of the three finger portions 112 with a single electric motor.

Next, the entire internal structure of the finger part 112 having the above-described inferior drive mechanism will be described with reference to FIG. In addition, in FIG. 11, a part of palm part 111 which is a hollow structure, and the outer shell of each link 116, 117, 118 are shown. About a wall part etc., illustration is abbreviate | omitted suitably and shown.

In FIG. 11, the base of the first link 116 is fixed to a first joint shaft 1131 provided at the edge of the palm 111, and the first joint shaft 1131 and the output shaft of the first motor 119 (actuator) are connected. They are connected by a coupling 121A. The first joint shaft 1131 is rotatably supported by a bearing 126A provided on the palm 111. With such a configuration, the entire finger portion 112 is swung (bent and extended) at the first joint 113 with respect to the palm portion 111 by the torque generated by the first motor 119.

A second motor 120 (actuator) is installed on the fingertip side of the first link 116. The output shaft of the second motor 120 and the second joint shaft 1141 are connected by a coupling 121B. The second joint shaft 1141 is rotatably supported by a bearing 126E provided at the base of the second link 117 and a bearing 126B provided on the first link 116. The drive pulley 122 is fixed to the second joint shaft 1141, and the drive pulley 122 and the second joint shaft 1141 coincide with each other in the rotation angle.

The third link 118 is connected to the fingertip side of the second link 117. The root of the third link 118 is fixed to the third joint shaft 1151. The third joint shaft 1151 is rotatably supported by a bearing 126D provided on the fingertip side of the second link 117. The third joint shaft 1151 is provided with a driven pulley 123. A belt 124 is stretched between the driving pulley 122 and the driven pulley 123, and torque of the driving pulley 122 is transmitted to the driven pulley 123 via the belt 124. The idle pulley 125 provided at the intermediate portion of the second link 117 is also in contact with the belt 124. The idle pulley 125 serves to adjust the tension of the belt 124. The driving pulley 122, the driven pulley 123, and the belt 124 correspond to an example of a torque transmission mechanism described in the claims.

A stopper 128 that restricts the posture of the second link 117 with respect to the first link 116 is provided at a location where the first link 116 and the second link 117 overlap in the second joint 114. The stopper 128 includes a pin 128 </ b> A provided on the first link 116 and a guide groove 128 </ b> B provided on the second link 117. Further, a stopper 129 that restricts the posture of the third link 118 with respect to the second link 117 is provided at a location where the second link 117 and the third link 118 overlap in the third joint 115. The stopper 129 includes a pin 129 </ b> A provided on the second link 117 and a guide groove 129 </ b> B provided on the third link 118.

An example of the configuration of the stopper 129 will be described with reference to FIGS. 12 and 13, the pin 129 </ b> A is erected on the inner side of the second link 117 where the second link 117 and the third link 118 overlap. The guide groove 129B is provided in the third link 118 so as to be parallel to the outer periphery around the third joint shaft 1151 where the third link 118 and the second link 117 overlap, and the guide groove 129B of the inserted pin 129A It is configured to be able to regulate the operating range. That is, as shown in FIG. 12, the stopper 129 prevents the axis of the second link 117 and the axis of the third link 118 from extending more than 180 degrees around the third joint axis 1151 and As shown, the second link 117 and the third link 118 are not bent at an acute angle (for example, 90 degrees or less) about the third joint axis 1151 so that the third link 118 has an axis of the third link 118 with respect to the second link 117. Limit posture. The stopper 128 has the same configuration as the stopper 129.

11, a coiled torsion spring 127 is provided around the second joint shaft 1141. Although not shown, one end of the torsion spring 127 is fixed to the first link 116, and the other end is fixed to the second link 117. Thus, the torsion spring 127 is gripped so that the driving torque required to drive the second joint 114 is smaller than the driving torque required to drive the third joint 115 during the gripping operation. During the releasing operation, the auxiliary torque is applied to the second joint 114 so that the driving torque necessary to drive the second joint 114 is larger than the driving torque necessary to drive the third joint 115. To do.

An example of the configuration of the torsion spring 127 will be described (FIG. 14). In FIG. 14, the stopper 128 is not shown. In FIG. 14, the torsion spring 127 is inserted around the second joint shaft 1141. One free end of the torsion spring 127 is fixed to a pin 135A provided in the first link 116, and the other free end of the torsion spring 127 is fixed to a pin 135B provided in the second link 117. Is done. The pins 135 </ b> A and 135 </ b> B are arranged so that the second link 117 is bent, for example, 90 degrees with respect to the first link 116 in a natural state where the power is not supplied to the second motor 120. The torsion spring 127 corresponds to an example of a drive torque adjusting member described in the claims, and also corresponds to an example of a second spring member.

Next, the operation of the finger part 112 of the robot hand 108 according to the present embodiment will be described with reference to FIG. The motor 119 drives the first joint shaft 1131 to control the posture of the first link 116, and the motor 120 drives the second joint shaft 1141 and the third joint shaft 1151. Since the motor 120, the second joint shaft 1141, and the third joint shaft 1151 are underactuated mechanisms, the motor 120 cannot arbitrarily control the angle of the third joint shaft 1151. An under-actuated mechanism is a mechanism that has a lower degree of actuator freedom than a degree of freedom to be controlled. The point that the input degree of freedom is smaller than the output degree of freedom is advantageous for familiar gripping (gripping so as to follow the object shape). In this embodiment, there are two joint shafts for one motor. In the object gripping process, first, the motor 119 controls the posture of the first link 116 so that the first link 116 approaches the gripping target 9. After the first link is controlled to a predetermined posture, the motor 120 drives the second link 117 and the third link so that the second link 117 and the third link 118 are in contact with the grasped object 9. The underdrive mechanism (the motor 120 drives the second link 117 and the third link 118) of this embodiment will be described in detail. When there is friction between the driving pulley 122, the driven pulley 123, and the belt 124, and a motor torque that exceeds the friction is generated, the third link 118 rotates around the third joint shaft 1151. This is called a rotation operation. When a motor torque smaller than the friction is generated, the second link 117, the third link 118, the belt 124, the driving pulley 122, and the driven pulley 123 rotate integrally around the second joint shaft 1141. This is called a revolution operation. Two joints can be driven by one motor by rotation and revolution. When the speed of the second motor 120 is controlled and the output shaft of the second motor 120 rotates clockwise as viewed from the right side in FIG. 11 (the fingertip side paper surface depth direction in FIG. 11), the second joint is connected via the coupling 121B. The shaft 1141 and the drive pulley 122 rotate clockwise. The revolving operation is continued until the second link 117 comes into contact with the gripping object 9, and when the second link 117 comes into contact with the gripping object 9, the motor speed deviation increases, so that the torque exceeding the friction reduces the speed deviation. Occurs and switches to autorotation. That is, after the second link 117 comes into contact with the grasped object 9, the third link 118 bends toward the object. Through a series of operations (spinning operation and revolving operation), the finger unit 112 of the present invention holds the holding object 9 so as to follow the object shape.

The order in which the links (the second link 117 and the third link 118) start to move is important for grasping the grasped object 9 stably with the hand, and the order during the bending operation is the third after the second link 117. The order of the link 118 and the extension operation is the second link 117 after the third link 118. A torsion spring 127 and a stopper 129 are provided to ensure this operation. The second link 117 may start extending during the extension of the third link 118.

First, the reason why the torsion spring 127 is provided around the second joint shaft 141 will be described. The torsion spring 127 works so that the third link 118 starts to move after the second link 117 with a small torque during the bending operation, and the second link 117 follows the third link 118 unless a large torque is applied during the extension operation. Work to move. With the addition of the torsion spring 127, a desired bending / extending operation can be realized in any posture. The stopper 129 is a component necessary for the extension operation. If a torsion spring is added and the stopper 129 is not provided, only the third link 118 works and the second link cannot move. That is, without the stopper 129, a desired extension operation cannot be realized. Further, when the second link 117 continues to extend, the stopper 128 has an angle between the second link 117 and the first link 116 with a certain angle (for example, 180 degrees) or more around the second joint axis 1141. Regulate not to become.

Next, an initial attitude control method when driving the second motor 120 will be described. Due to the biasing force of the torsion spring 127, when the power of the second motor 120 is not turned on and the brake is not applied, the second link 117 is in the bending posture (the posture in the gripping direction). That is, the initial state of the second link 117 is a bent posture due to the influence of the torsion spring 127. However, when gripping an object, it is desirable that the second link 117 and the third link 118 are in the extended posture. Therefore, a voltage command is given from the PC 3 to the second motor 120 so as to rotate counterclockwise when viewed from the right side in FIG. 11 (toward the fingertip side in FIG. 11), and a torque that counters the biasing force of the torsion spring 127 is applied. And the extension operation of the second link 117 is executed. At this time, the extension operation of the third link 118 is stopped by the stopper 129, and the extension operation of the second link 117 is stopped by the stopper 128. The state in which the first link 116, the second link 117, and the third link 118 are extended in series is set as an initial posture, and the initial angle of the second motor 120 is stored in the memory of the PC 3 as 0 degree. Further, the angle difference (rotation angle) when restrained by the stopper 128 and the angle before the power is turned on is also stored in the PC 3. The angle difference 0 is used to return to the initial posture after the power is turned on, and the initial posture can be easily maintained by giving the angle difference as a target angle command.

According to the robot hand 108 according to the second embodiment described above, the finger 112 is provided with the conforming mechanism US having the driving pulley 122, the driven pulley 123 and the belt 124 as the torque transmission mechanism, and the torsion spring 127. During the gripping operation, the second joint 114 is driven to bend before the third joint 115, and during the grip releasing operation, the third joint 115 is driven to extend before the second joint 114. By selecting a torsion spring 127 that can hold the weight of the second link 117 and the third link 118, the finger 112 can flexibly grasp the shape of the grasped object 9 in any posture. . In any posture, bending and extension can be switched only by the rotation direction of the second motor 120. Furthermore, since there is only one motor and there are few force transmission parts, the entire finger portion can be reduced in weight, and the finger can be operated at high speed.

In this embodiment, in particular, the finger portion 112 is provided with a stopper 129 that restricts the posture of the third link 118 with respect to the second link 117. As a result, when the grip releasing operation is executed, first, the third link 118 starts to extend, the operation of the third link 118 is stopped at a predetermined angle, and then the second link 117 is extended. it can. That is, the extension operation of the second link 117 can be reliably started after the extension of the third link 118.

In addition, it is not restricted to the said embodiment, A various deformation | transformation is possible within the range which does not deviate from the meaning and technical idea. Hereinafter, such modifications will be described in order.

(2-1) When the second motor is disposed in the link In the second embodiment, the second motor 120 is disposed outside the second link 116 so that the output shaft of the second motor 120 and the second joint shaft 1141 coincide with each other. However, it is preferable to arrange the second motor 120 so as not to interfere with the other fingers 112. Therefore, the second motor 120 may be disposed inside the first link 116. This modification will be described with reference to FIG. However, only those related to the arrangement of the second motor 120 will be described.

In FIG. 15, the second motor 120 of this modification is fixed inside the first link 116. The output shaft 131 of the second motor 120 is supported by a bearing 132A disposed on the outer shell of the first link 116, and a gear 130A is coupled to the output shaft 131. A gear 130 </ b> C is connected to the second joint shaft 1141 in parallel with the drive pulley 122. A gear 130B (idle gear) is disposed inside the first link 116 so as to mesh with the gears 130A and 130C. The idle gear shaft 133 connected to the gear 130B is supported by a bearing 132B disposed on the outer shell of the first link 116. Other configurations are the same as those in the second embodiment.

Next, the operation will be described. When the output shaft 131 of the second motor 120 rotates clockwise as viewed from the right side in FIG. 15 (the fingertip side paper surface depth direction in FIG. 15), the gear 130A similarly rotates clockwise, and the gear 130B meshing with the gear 130A becomes Rotates counterclockwise. The gear 130C meshing with the gear 130B rotates clockwise. As a result, the second joint shaft 1141 connected to the gear 130C also rotates clockwise. Thereafter, the operation is the same as that of the second embodiment described above, and the second link 117 and the third link 118 are bent in the depth direction in the drawing to grip the object 9 to be grasped. Further, when the second motor 120 rotates counterclockwise as viewed from the right side in FIG. 15 (the fingertip side in FIG. 15), the second joint shaft 1141 rotates counterclockwise together with the gear 130C in the same manner as described above. To do. As a result, the third link 118 and the second link 117 are extended in the forward direction in the drawing.

This modification also achieves the same effect as that of the second embodiment. Further, as shown in FIG. 15, the torsion spring 127 can be installed at both ends of the second joint shaft 1141 because the coupling 121B need not be provided, so that the auxiliary torque can be increased. In this modification, the gear 130B is provided in order to make the rotation direction of the second motor 120 the same as the rotation direction of the second joint 114 and the third joint 115, but it is not necessary to match the rotation direction. The gear 130B may be omitted. In this case, further weight reduction can be achieved.

(2-2) When the second motor and the worm gear are arranged in the link This modified example is an example in which a worm gear is used instead of a spur gear in the configuration of the modified example (2-1). This modification will be described with reference to FIG.

16, the second motor 120 is disposed inside the first link 116 so that the axial direction is along the longitudinal direction of the link. The output shaft 131 of the second motor 120 is connected to a worm 134, and the worm 134 is supported by bearings 136 </ b> A and 136 </ b> B installed inside the first link 116. A gear 130A is disposed so as to mesh with the worm 134, and a gear 130B is disposed inside the first link 116 so as to mesh with the gear 130A and the gear 130C. The gear 130 </ b> C is coupled to the second joint shaft 1141 in parallel with the drive pulley 122 in the same manner as described in the modification (2-1).

Next, the operation will be described. When the worm 134 rotates counterclockwise as viewed from the upper side in FIG. 16 by driving the second motor 120, the gear 130A rotates counterclockwise, the gear 130B rotates clockwise, and the gear 130C rotates counterclockwise. Accordingly, when the second joint shaft 1141 rotates counterclockwise similarly to the gear 130C, the second link 117 and the third link 118 are bent. On the other hand, when the worm 134 rotates clockwise as viewed from the upper side in FIG. 16, the second link 117 and the third link 118 extend.

This modification also achieves the same effect as that of the second embodiment. Further, the use of the worm 134 has an effect of reducing the power consumption of the second motor 120 for maintaining the posture of the second link 117 and the third link 118.

(2-3) In the case where the auxiliary torque is applied by the tension spring In the second embodiment, the auxiliary torque is applied to the second joint 114 by the torsion spring 127, but a tension spring is used instead of the torsion spring 127. May be. This modification will be described with reference to FIG.

In FIG. 17, one end of the first wire 138A is fixed to a pin 135A provided in the first link 116, and the other end of the first wire 138A is connected to the end of the coiled tension spring 137. It is connected. The other end of the tension spring 137 is connected to the second wire 138B, and the second wire 138B is fixed to a pin 135B provided inside the second link 117. A part of the first wire 138A is in contact with a pulley 139 that is rotatably supported by the second joint shaft 1141. The pulley 139 is installed in parallel with the drive pulley 122. Also in this case, the pins 135A and 135B are arranged so that the second link 120 is in a state in which the power is not turned on and the second link 117 is bent, for example, 90 degrees with respect to the first link 116. Also by this modification, the same effect as the second embodiment is obtained. The tension spring 137 corresponds to an example of a drive torque adjusting member described in the claims, and also corresponds to an example of a second spring member.

(2-4) In the case of having a finger part composed of two links In the second embodiment, the case where each finger part 112 is composed of three links 116, 117, and 118 has been described as an example. A conforming mechanism US may be provided for a finger portion composed of two links. This modification will be described with reference to FIGS.

In FIG. 18, in the robot hand 108, the finger part 212 corresponding to the thumb connects two links 216 and 217 in series via the second joint 214, and the palm side link 216 passes through the first joint 213. The structure is connected to the palm 111. The configuration of the other two fingers 112 is the same as that of the second embodiment. The finger part 212 can be bent on a plane that is inclined with respect to the swinging surface of the other finger part 112. The robot hand 108 can grip the object 9 by bending the three finger portions 112 and 212 so as to be close to each other.

In FIG. 19, the output shaft of the first motor 219 (actuator) and the first joint shaft 2131 are connected by a coupling 221 at the edge of the palm 111. The first joint shaft 2131 is rotatably supported by a bearing 226A provided on the palm 111 and a bearing 226C provided on the first link 216. With such a configuration, the entire finger portion 212 is bent at the first joint 213 with respect to the palm portion 111 by the torque generated by the first motor 219.

The principle of driving the first joint shaft 2131 and the second joint shaft 2141 by the first motor 219 is the same as the principle of driving the second joint shaft 1141 and the third joint shaft 1151 by the second motor 120 of FIG. is there.

The second link 217 is connected to the fingertip side of the first link 216. The root of the second link 217 is fixed to the second joint shaft 2141. The second joint shaft 2141 is rotatably supported by a bearing 226B provided on the fingertip side of the first link 216. A driven pulley 223 is provided on the second joint shaft 2141. A belt 224 is stretched between the driving pulley 222 and the driven pulley 223, and torque of the driving pulley 222 is transmitted to the driven pulley 223 via the belt 224. The driving pulley 222, the driven pulley 223, and the belt 224 correspond to an example of a torque transmission mechanism described in the claims.

Around the first joint shaft 2131, coiled torsion springs 227 are provided at both ends thereof. Each torsion spring 227 has one end fixed to the palm 111 and the other end fixed to the first link 216. The torsion spring 227 drives the second joint shaft 2141 after the first joint shaft 2131 during the bending operation, and drives the first joint shaft 2131 after the second joint shaft 2141 during the extension operation, regardless of the posture of the hand 108. Acts to be. The torsion spring 227 applies an auxiliary torque to the first joint 213.

The first joint 213 is provided with a stopper 228 that restricts the posture of the first link 216 with respect to the palm 111. The stopper 228 restricts the posture so that the palm 111 and the first link 216 do not extend, for example, 180 degrees or more around the first joint axis 2131. When the first link 216 is bent, the first link 216 contacts the end surface 1111 of the palm 111 so that the palm 111 and the first link 216 are not bent at an acute angle (for example, 90 degrees or less). , Posture is limited. A stopper 229 that restricts the posture of the second link 217 with respect to the first link 216 is provided at a location where the first link 216 and the second link 217 overlap in the second joint 214. This stopper 229 has a posture so that the first link 216 and the second link 217 do not extend more than 180 degrees around the second joint axis 2141 and do not bend at an acute angle (for example, 90 degrees or less). Restrict. Further, the stopper 229 acts to reliably drive the first joint shaft 2131 after the second joint shaft 2141 during the extension operation. The configuration of these stoppers 228 and 229 is the same as that of the stoppers 128 and 129 described above.

As described above, in this modification, the finger 212 is provided with the conforming mechanism US having the driving pulley 222, the driven pulley 223, the belt 224, and the torsion spring 227 as the torque transmission mechanism, and drives the first joint 213. By adjusting the driving torque necessary to do this, it is possible to grip the object to be gripped with the finger part 212 so as to be wrapped.

Next, another configuration example of the finger unit 212 will be described with reference to FIGS. In the example shown in FIG. 20, the finger part 212 corresponding to the thumb of the robot hand 108 is configured by connecting two links 216 and 217. Unlike the example shown in FIG. 19, the palm-side first link 216 is The second link 217 is bent through a first joint 213 on a plane that is substantially perpendicular to the swing plane of the other two fingers 112, and the second link 217 is moved through the second joint 214. Can be bent on a plane parallel to the surface.

The first joint shaft 2131 connected to the output shaft of the first motor 219 with the coupling 221 is provided with a bevel gear 230. The bevel gear 230 meshes with a drive pulley 222 having a bevel gear shape. A belt 224 is stretched between the driving pulley 222 and a driven pulley 223 provided on the second joint shaft 2141, and torque of the driving pulley 222 is transmitted to the driven pulley 223 via the belt 224. . The point that the coiled torsion spring 227 is provided around the first joint shaft 2131 and the point that the stoppers 228 and 229 are provided on the first joint shaft 213 and the second joint shaft 214 are shown in FIG. The configuration is the same as that shown in FIG.

Next, the operation of the finger unit 212 will be described with reference to FIG. 21A and 21B are views of the robot hand 108 viewed from the wrist direction (lower side in FIG. 20), and FIG. 21C is a side view viewed from the side direction (right side in FIG. 20). It is a figure. When the output shaft of the first motor 219 rotates clockwise as viewed from the lower side in FIG. 20 (clockwise in FIG. 21), the first joint shaft 2131 and the bevel gear 230 rotate clockwise through the coupling 221. Rotate. As a result, the first link 216 rotates together with the first joint shaft 2131, and the first link 216 bends from the state shown in FIG. 21A to the grasped object 9 side (the front side in FIG. 20). When the palm portion 111 and the first link 216 become, for example, 90 degrees by the bending operation, the first link 216 comes into contact with the end surface 1111 of the palm portion 111 as shown in FIG. The bending motion of 216 stops. Further, when the output shaft of the first motor 219 rotates clockwise, the torque of the first motor 219 is transmitted from the bevel gear 230 to the driven pulley 223 via the drive pulley 222 and the belt 224, and the second joint shaft 2141 is rotated clockwise. As shown in FIG. 21 (c), the second link 217 is bent until it comes into contact with the grasped object 9. In this way, since the finger part 212 brings the second link 217 into contact with the grasped object 9 after the first link 216, the operation of being familiar with the grasped object 9 is executed.

The same effects as those of the second embodiment can be obtained by the modification described above.

(2-5) In the case where the internal / external movement of the finger is possible In the second embodiment, the internal rotation that brings the fingers close to each other and the abduction that moves the fingers apart are not considered. However, in order to enable flexible gripping according to the shape of the gripping target, it is possible to adopt a configuration capable of inward and outward rotation operations. This modification will be described with reference to FIGS.

22, the robot hand 300 includes a palm portion 311 and three finger portions 312, 313, and 314 having roots connected to the palm portion 311. The finger 312 will be described as an example. The finger 312 includes four links 301, 302, 303, and 304, and adjacent links are connected. The root link 301 is connected to a gear 305, and the gear 305 meshes with the gear 306. Accordingly, the root link 301 is swung on a plane parallel to the palm portion 311 by the drive motor 307 of the gear 306. Similarly, the gear 309 connected to the root link 315 of the finger portion 313 meshes with the gear 306 via the gear 308. Thereby, the root link 315 is swung on a plane parallel to the palm portion 311 by the drive motor 307. The gear 308 is provided so that the rotation directions of the gear 305 and the gear 309 are opposite (for example, when the gear 305 rotates clockwise, the gear 309 rotates counterclockwise). The finger portion 314 is swung on a plane parallel to the palm portion 311 by a drive motor 310 connected to the root link 316.

By adopting such a configuration, it is possible to realize the inner / outer rotation operations of the two finger portions 312 and 313 with one drive motor 307. Therefore, the number of motors can be reduced and costs can be reduced as compared with the case where a drive motor is provided for each finger.

Next, the structure of the palm 311 will be described with reference to FIG. In FIG. 23, the root link 301 is disposed between the palm 311 and the upper 317, and the drive motors 307 and 310 are installed on the upper 317. The palm portion 311 and the upper portion 317 are fixed by a plurality of bolts 318 with the spacer 350 interposed therebetween. The output shaft of the drive motor 307 is connected to a shaft 320, and the shaft 320 is supported by a bearing 319 provided inside the palm portion 311 and a bearing 321 provided inside the upper portion 317. On the other hand, the shaft 322 connected to the root link 301 is also supported by the bearing 319 and the bearing 321. The gear 306 connected to the shaft 320 and the gear 305 connected to the shaft 322 are meshed with each other.

Thus, the motor replacement can be easily performed by arranging the drive motors 307 and 310 on the upper part 317 side.

Next, the schematic structure inside the finger will be described with reference to FIG. Since the finger parts 313 and 314 have the same configuration as the finger part 312, only the finger part 312 will be described here. A motor 330 (actuator) is arranged inside the root link 301, and an output shaft of the motor 330 is connected to a bevel gear 323. The bevel gear 323 meshes with the first joint pulley 325 and the coaxial bevel gear 324. In order to transmit the driving force of the first joint pulley 325 to the second joint pulley 327, the belt 326 is stretched over the pulleys 325 and 327. Similarly, the driving force of the second joint pulley 327 is transmitted to the third joint pulley 329. Is transmitted to pulleys 327 and 329. The rotational torque of the motor 330 works as a force for bending / extending each link.

Although detailed description is omitted, here, torsion springs (not shown) are provided at the first joint 331 and the second joint 332 of the finger 312. Accordingly, in the torsion spring, the driving torque necessary for driving the first joint 331 is smaller than the driving torque necessary for driving the second joint 332 and the third joint 333 during the gripping operation. As described above, the first driving torque required to drive the second joint 332 is smaller than the driving torque required to drive the third joint 333. Necessary for driving the second joint 332 such that the driving torque necessary for driving the joint 331 is larger than the driving torque necessary for driving the second joint 332 and the third joint 333. Auxiliary torque is applied to the first joint 331 and the second joint 332 so that the driving torque is greater than the driving torque required to drive the third joint 333.

Although not shown, stoppers similar to those in the second embodiment described above are provided between the links 301 and 302, between the links 302 and 303, and between the links 303 and 304.

As described above, according to the present modification, the conforming mechanism US including the pulleys 325, 327, and 329 as the torque transmission mechanism, the belts 326 and 328, and the torsion spring is provided, and the torsion spring includes the joints 331, 332, and 333. The drive torque required to drive the is adjusted. Accordingly, during the gripping operation, the first joint 331, the second joint 332, and the third joint 333 are bent and driven in this order, and during the grip releasing operation, the third joint 333, the second joint 332, and the first joint are driven. The extension is driven in the order of the joint 331. With any torsion spring, it is possible to grip the object to be gripped with the finger portion 312 in any posture.

Next, the operation of the robot hand 300 will be described with reference to FIGS. 25 and 26 show a state in which a relatively large gripping object 9 is gripped by the hand robot 300. FIG. In this case, the image of the grasped object 9 is, for example, an empty can. When gripping the side surface of the object 9 to be gripped with the three finger portions 312, 313, and 314, each finger portion does not perform adduction / extraction, and first the first link contacts a part of the palm. After the operation is completed, the second link comes into contact with the can, and the third link comes into contact with another part of the can to complete the gripping operation. As a result, it is gripped so as to adapt to the shape of the can.

27 and 28 show a state where the hand robot 300 grips a relatively small gripping object 9. In this example, the grasped object 9 is a rectangular parallelepiped object and is grasped by the two finger portions 312 and 314. At this time, the first link of the finger portions 312 and 314 contacts a part of the palm, and after the operation is completed, the second link does not contact the gripping object 9 and the third link contacts the gripping object 9. Complete the gripping motion.

In the above description, the case where the grasped object 9 is grasped by the finger portions 312 and 314 is shown as an example. However, the finger portions 312 and 313 may be grasped, and the finger portions 312 and 313 may have an angle of 180 with respect to each other. It may be abbreviated so as to be gripped by these finger portions 312 and 313.

According to this modified example described above, it is possible to hold the grasped object 9 with the finger portions 312, 313, and 314 in any posture as in the second embodiment described above. is there. As a result, the robot hand 300 can perform a flexible grip on the grip target 9 according to the shape of the target 9. Further, since the three joints are driven by one motor, the weight of the fingers can be further reduced and the cost can be reduced as compared with the second embodiment.

Next, another configuration example of the robot hand 300 will be described with reference to FIG. In the above modification, the motor 330 that swings (bends and extends) the finger part is built in the root link 301. However, in order to reduce the weight of the finger part 312, it is better to place the motor 330 outside the finger part. good. In FIG. 29, the motor 330 installed on the upper 317 is connected to a shaft 332, and a worm 331 is connected to the root link 301 on the shaft 332. A worm wheel 333 is arranged inside the root link 301 so as to mesh with the worm 331. A gear 334 is disposed in the middle to transmit the rotation of the worm wheel 331 to the first joint pulley 325. The gear 334 meshes with a gear 335 disposed so as to be coaxial with the first joint pulley 325. As a result, the first link 302, the second link 303, and the third link 304 can be swung (bended and extended) by the motor 330 of the upper part. A bearing (not shown) is provided inside the gear 305 so that the torque of the motor 330 and the gear 305 do not interfere with each other, and the gear 305 and the root link 301 are connected. The other configurations for driving the first link, the second link, and the third link are the same as those in FIG.

(2-6) Others The first motor and the second motor described above may have a configuration in which not only a motor but also a speed reducer is coupled. In that case, the output torque increases. In addition, the belt may be a wire in which a thin wire (made of metal or nylon) is wound around the core of the wire, and the wire ends are connected with metal via a drive pulley, a driven pulley and an idle pulley. In this case, if the drive pulley, the driven pulley, and the idle pulley are made of resin material, the drive transmission system becomes light.

<Third Embodiment>
Next, a third embodiment will be described. This embodiment can adjust the driving torque necessary to drive the joint by restraining the driving of the joint shaft on the fingertip side by the joint restraining mechanism of the conforming mechanism, and can grip the object so as to wrap the object with the finger It is what.

About the structure of the robot apparatus 1 and the robot main body 2 provided with the robot hand which concerns on this embodiment, it is the same as that of above-mentioned 1st Embodiment (FIG. 1), About the structure of the robot hand which concerns on this embodiment, Since it is the same as that of above-mentioned 2nd Embodiment (FIG. 10), description is abbreviate | omitted.

Next, the internal structure of the entire finger part 400 of the robot hand according to the present embodiment will be described with reference to FIGS. First, the planetary gear mechanism 401 included in the finger 400 will be described with reference to FIG. In FIG. 30, the planetary gear mechanism 401 includes a shaft 4101 that inputs output torque from the coupling 409 to the sun gear 4102, a planetary gear 4103 that inputs the output of the sun gear 4102 to the carrier 4104, and a carrier cup provided on the carrier 4104. 4105, when the carrier cup 4105 stops rotating, the planetary gear 4103 that inputs the output of the sun gear 4102 to the ring gear 4106, the ring gear cup 4107 having the ring gear 4106 inside, and the ring gear cup 4107 are freely rotatable. And a case 4108 that protects the planetary gear mechanism 401. Further, teeth are provided on the upper surfaces of the carrier cup 4105 and the carrier cup 4107. The planetary gear mechanism 401 corresponds to an example of a torque transmission mechanism described in the claims.

Next, the internal structure of the finger part 400 will be described with reference to FIG. In FIG. 31, in the finger part 400, the carrier cup 4105 of the planetary gear mechanism 401 swings the second link 417 via the gear 403 in the depth direction and the front side of the page in FIG. However, the stopper 423 prevents the second link 417 from warping in the forward direction of the drawing. The base sides of the gear 403 and the second link 417 are connected to the second joint shaft 407 of the second joint 425. That is, the rotation of the gear 403 causes the second link 417 to rotate around the second joint shaft 425, and the finger 400 is bent at the second joint 425.

On the other hand, the ring gear cup 4107 of the planetary gear mechanism 401 rotates the third joint shaft 420 of the third joint 424 via the gear 405, the bevel gears 406 and 415, the shaft 416, and the bevel gears 418 and 419, thereby The link 421 is swung in the depth direction and the front side of the page. However, the stopper 423 prevents the third link 421 from warping in the forward direction of the drawing. The relative angular displacement between the gear 405 and the bevel gear 406 is constrained to be zero, and the gears 405 and 406 are freely rotatable with respect to the second joint shaft 425. That is, although not shown in the drawing, bearings are built in the gears 405 and 406. The spring 422 restrains the relative angle between the third link 421 and the second link 417 to be zero. The drive of the third joint shaft 420 by the spring 422 is restrained until the second link 417 contacts the object 9 to be gripped and the second joint shaft 407 stops rotating, during which the ring gear cup 4107 remains stationary. To do.

The driving torque of the planetary gear mechanism 401 is a differential torque of two pairs of motors 413 (actuators), and is input to the sun gear 4102 of the planetary gear mechanism 401 via the bevel gears 411 and 412, the shaft 410, and the coupling 409. Is done. The combined torque of the two pairs of motors 413 is a torque for swinging the first link 414 around the first joint axis 426 in the depth direction and the front side of the page.

Normally, the planetary gear mechanism is a mechanism that fixes one of the sun gear, the carrier, and the ring gear, and decelerates or increases the output with respect to the input. In this embodiment, the input is a sun gear 4102, and the output is a carrier 4104 and a ring gear 4106. However, in this state, it is not determined which of the carrier 4104 and the ring gear 4106, which are outputs, starts to move first, or moves simultaneously. Here, the ring gear 4106 is indirectly restrained by the spring 422 so that the second joint 425 starts to move before the third joint 424 during the gripping operation. In this way, familiar gripping can be realized even with an underactuated finger by the planetary gear mechanism 401.

As described above, in this embodiment, the finger part 400 includes the sun gear 4102, the carrier 4104, and the ring gear 4106, and the carrier 4104 is indirectly connected to the second joint shaft 407 and the ring gear 4106 is indirectly connected to the third joint shaft 420. The planetary gear mechanism 401 and the gripping operation are performed so that the driving torque required to drive the second joint shaft 407 is smaller than the driving torque required to drive the third joint shaft 420. A conforming mechanism US having a spring 422 that restricts the rotation of the three joint shaft 420 (in other words, adjusts the driving torque of the third joint shaft to be increased) is provided, and is necessary for driving the third joint 424. By adjusting the driving torque, it is possible to grip the object 9 with the finger 400 so as to wrap it. The spring 422 corresponds to an example of a drive torque adjusting member and a joint restraining mechanism described in the claims.

Further, by using the interference mechanism, the angle of the first link 414 is controlled by the combined torque, and the angle of the second link 417 and the third link 421 is controlled by the differential torque. For example, consider a case where a two-fingered robot hand grips one point on the inner periphery and one point on the outer periphery of a donut-shaped object (such as a packing tape). First, the posture of the first link is controlled so that two fingers are arranged on the inner periphery and outer periphery of the donut-shaped object. Thereafter, by controlling the posture of the second and third links, it becomes possible to grip one point on the inner periphery and one point on the outer periphery of the donut-shaped object. In this way, posture control can be realized even in inferior drive.

Next, the operation principle of the conforming mechanism US in the finger 400 will be described with reference to FIG. 32, the planetary gear mechanism 401 includes a sun gear 4102, a planetary gear 4103, a carrier 4104, and a ring gear 4106. The ring gear 4106 is indirectly restrained by the spring 422 as described above. The spring 422 is disposed between the second link 417 and the third link 421. FIG. 32A shows a state where the input torque to the sun gear 4102 is zero. Next, as shown in FIG. 32 (b), when a clockwise torque is input to the sun gear 4102, the planetary gear 4103 rotates, and at the same time, the carrier 4104 rotates in the same clockwise direction. As a result, the second link 417 moves toward the grasped object 9 about the second joint axis 407. At this time, since the ring gear 4106 is stopped by the third joint shaft 420 being restrained by the spring 422, the relative angle between the second link 417 and the third link 421 is zero. Thereafter, when the second link 417 contacts the grasped object 9, the driving of the second joint shaft 407 is restrained, and the carrier 4104 is restrained. As a result, as shown in FIG. 32C, counterclockwise torque is generated in the ring gear 4106, and the third link 421 moves toward the grasped object 9 about the third joint shaft 420. When the first link 414, the second link 417, and the third link 421 come into contact with the object 9 to be grasped, both the carrier 4104 and the ring gear 4106 are restrained, and the planetary gear 4103 and the sun gear 4102 are stopped.

According to the third embodiment described above, the finger unit 400 is provided with the conforming mechanism US having the planetary gear mechanism 401 as the torque transmission mechanism and the spring 422, and the second joint 425 and the second joint 425 are provided in the gripping operation. By bending the three joints 424 in this order and adjusting the driving torque necessary to drive the third joint 424, it is possible to grip the gripping object with the finger 400 in any posture. It is said. Thereby, the robot hand can perform a flexible grip on the grip target 9 according to the shape of the target 9.

In addition, it is not restricted to the said embodiment, A various deformation | transformation is possible within the range which does not deviate from the meaning and technical idea. Hereinafter, such modifications will be described in order.

(3-1) In the case of a planetary gear mechanism that transmits torque using a pulley In the third embodiment, teeth are provided on the upper surfaces of the carrier cup 4105 and the ring gear cup 4107, and torque is transmitted using the teeth. However, the present invention is not limited to this, and a configuration may be adopted in which torque is transmitted using a pulley. This modification will be described with reference to FIG.

In FIG. 33, the planetary gear mechanism 401 is provided with pulleys 4109 and 4110 on the outer circumferences of the carrier cup 4105 and the ring gear cup 4107, respectively, and a hole (or gap) 4111 that allows belt transmission in the case 4108. . Other configurations are the same as those of the third embodiment. Also according to this modification, the same effect as the third embodiment is obtained.

(3-2) When using a joint restraint mechanism for restraining the shaft In the third embodiment, the third joint 424 is restrained by restraining the relative angle between the third link 421 and the second link 417 using a spring. However, the present invention is not limited to this, and the shaft 416 may be restrained. This modification will be described with reference to FIG.

34, a joint restraining mechanism JC that restrains driving of the third joint shaft 420 is provided inside the second link 417. The joint restraining mechanism JC includes a stopper 505, a spring 504 provided on one side of the stopper 505, and a support member 506 provided on the other side of the stopper 505 and connecting the stopper 505 and the pad 503. ing. FIG. 34A shows a state before the second link 417 comes into contact with the grasped object 9, and FIG. 34B shows a state after the second link 417 comes into contact with the grasped object 9. Represents. As shown in FIG. 34A, the stopper 505 is in contact with the shaft 416 by the weight of the spring 504 and the stopper 505 before the second link 417 contacts the grasped object 9. When the shaft 416 is restrained by the stopper 505, the ring gear cup 4107 is restrained, and the relative angle between the second link 417 and the third link 421 becomes zero. When the pad 503 comes into contact with the grasped object 9 and the support member 506 is pushed into the second link 417, the spring 504 contracts, the stopper 505 is detached from the shaft 416, and the shaft 416 is not restrained. As a result, the output torque of the sun gear 4102 is transmitted to the ring gear 4106 and the ring gear cup 4107 rotates. With this rotation, the third link 421 swings. 34C is a side sectional view of the second link 417. As shown in FIG. 34C, the stopper 505 is configured to partially cover the shaft 416. FIG.

With the above configuration, the joint restraining mechanism JC is configured so that the driving torque necessary to drive the second joint 425 is smaller than the driving torque necessary to drive the third joint 424 during the gripping operation. The drive of the joint shaft 420 of the third joint 424 is constrained. Thereby, it is possible to hold the object to be held by the finger unit 400 so as to be wrapped.

(3-3) When using a joint restraint mechanism for restraining the ring gear cup In the third embodiment, the drive of the third joint 424 is restrained by restraining the shaft. The ring gear cup 4107 of the gear mechanism 401 may be restrained. This modification will be described with reference to FIG.

As shown in FIG. 35A, the robot hand has a three-joint finger unit 400 including a first link 414, a second link 417, and a third link 421, and a palm unit 606. . The planetary gear mechanism 401 described above is built in the first link 414. A contact sensor 605 is provided outside the second link 417. As the contact sensor 605, a sensor that receives stress and outputs an electrical signal (for example, a strain gauge, a pressure sensor, or the like) is used. The electrical signal from the contact sensor 605 is input to the amplifier 608 inside the second link 417 via the cable 607, and the amplified signal is applied to the shape memory alloy 610 inside the first link 414 via the cable 609.

As shown in FIG. 35B, the joint restraining mechanism JC inside the first link 414 includes a stopper 611 that restrains the ring gear cup 4107, and a coil-shaped shape memory alloy that connects the inside of the first link 414 and the stopper 611. 610, a shape memory alloy 610, and a cable 609 for applying a current to the spring 613. When the contact sensor 605 is not in contact with the object 9 to be grasped, the current applied to the shape memory alloy 610 is small. Therefore, as shown in FIG. The gear cup 4107 is restrained. On the other hand, when the contact sensor 605 comes into contact with the object 9 to be grasped, a current is applied to the shape memory alloy 610, so that the shape memory alloy 610 contracts and the stopper 611 becomes the ring gear cup 4107 as shown in FIG. The restraint is removed from the distance. As a result, the ring gear cup 4107 is rotated by the torque transmitted from the sun gear 4102 of the planetary gear mechanism 401 to the ring gear 4106. With this rotation, the third link 421 swings. Also according to this modification, the same effect as the third embodiment is obtained.

(3-4) When using a wave gear mechanism as the torque transmission mechanism In the third embodiment, the planetary gear mechanism is used as the torque transmission mechanism. However, the present invention is not limited to this, and a wave gear mechanism may be used. This modification will be described with reference to FIGS. 36 and 37. FIG.

As shown in FIG. 36A, the wave gear mechanism 700 includes a wave generator 701, a flex spline 702, and a circular spline 703. As shown in FIG. 36B, in this embodiment, a flex spline cup gear 704 is provided in the flex spline 702, and a circular spline cup gear 705 is provided in the circular spline 703. Further, a bearing 706 is disposed between the circular spline 703 and the case 707, and the circular spline 703 is rotatably supported. With such a configuration, the wave gear mechanism 700 is a 1-input 2-output torque transmission mechanism similar to the planetary gear mechanism 401 of the third embodiment. In this modification, the wave gear mechanism 700 is used for driving the second joint 425 and the third joint 424 of the robot hand, so that the planetary gear mechanism 401 of the finger 400 shown in FIG. The same operation can be realized. At this time, the input is a wave generator 701, and the output is a flex spline cup gear 704 and a circular spline cup gear 705.

This modification also achieves the same effect as the third embodiment. Moreover, since there are few gear parts compared with the case where a planetary gear mechanism is used, there also exists an effect which can make a finger part lightweight.

Next, another configuration example of the wave gear mechanism 700 will be described with reference to FIG. In FIG. 37, a flex spline 702 (not shown in FIG. 37) is provided with a flex spline cup 708 and a pulley 709, and a circular spline 703 is provided with a pulley 710. A belt (not shown) is stretched between these pulleys 709 and 710 and a pulley provided on the finger of the robot hand, and torque is transmitted. Other configurations are the same as described above. Also according to this modification, the same effect as the third embodiment is obtained. In this case, the wave gear mechanism 700 described in the present modification can be accommodated in the palm of the hand by lengthening the belt between the pulleys 709 and 710 and the pulley provided on the finger of the robot hand. The finger can be lightened.

In addition to those already described above, the methods according to the above embodiments and modifications may be used in appropriate combination.
In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

1 Robotic device 3 Personal computer (controller)
8 Robot Hand 9 Grasping Object 11 Palm 12, 12 A Finger 13 First Joint 14 Second Joint 15 Third Joint 16 First Link 17 Second Link 18 Third Link 19 Twist Joint Part 24 First Joint Drive Motor ( Actuator, 1st actuator)
25 Second joint drive motor (actuator, second actuator)
26 first joint drive gear 27 first joint driven gear 30 second joint drive gear (second link drive transmission mechanism, third link drive transmission mechanism)
31 Second joint driven gear (second link drive transmission mechanism, third link drive transmission mechanism)
32 third joint drive pulley (pulley mechanism, third link drive transmission mechanism)
33 third joint driven pulley (pulley mechanism, third link drive transmission mechanism)
34 Belt (belt member, pulley mechanism, third link drive transmission mechanism)
35 First small link (small link member)
36 Second small link (small link member)
38 Twist mechanism 38A to C Twist mechanism 41 Shaft support plate 42, 42B Shaft (shaft member)
43 Guide plate 44 Shaft bearing (bearing member)
45, 45B Guide rod (guide member, regulating member)
46 Torsion spring (first spring member, restoring force applying member)
47 Guide groove (guide member, regulating member)
48 through hole 49 cable member 51 helical spring (spring member, restoring force applying member)
52 Permanent magnet (restoring force applying member)
53 Rubber member housing 54 Connecting member 55 Pressing member 56 Rubber member (restoring force applying member)
57 deep groove 108 robot hand 111 palm part 112 finger part 113 first joint 114 second joint 115 third joint 116 first link 117 second link 118 third link 119 first motor (actuator)
120 Second motor (actuator)
122 Drive pulley (torque transmission mechanism)
123 Driven pulley (torque transmission mechanism)
124 belt (torque transmission mechanism)
127 Torsion spring (drive torque adjusting member, second spring member)
128,129 Stopper 129A Pin 129B Guide groove 137 Tension spring (drive torque adjusting member, second spring member)
138A, B Wire 212 Finger part 213 First joint 214 Second joint 216 First link 217 Second link 219 First motor (actuator)
222 Drive pulley (torque transmission mechanism)
223 Driven pulley (torque transmission mechanism)
224 belt (torque transmission mechanism)
227 Torsion spring (drive torque adjusting member, second spring member)
229 Stopper 300 Robot hand 301 Root link 302 First link 303 Second link 304 Third link 311 Palm portion 312 to 314 Finger portion 330 Motor (actuator)
331 First joint 332 Second joint 333 Third joint 400 Finger part 401 Planetary gear mechanism (torque transmission mechanism)
407 Second joint shaft 413 Motor (actuator)
414 1st link 417 2nd link 420 3rd joint axis 421 3rd link 422 Spring (drive torque adjustment member, joint restraint mechanism)
424 3rd joint 425 2nd joint 426 1st joint 700 Wave gear mechanism (torque transmission mechanism)
701 Wave generator 702 Flex spline 703 Circular spline 1141 2nd joint axis 1151 3rd joint axis 2131 1st joint axis 2141 2nd joint axis 4102 Sun gear 4104 Carrier 4106 Ring gear CL Rotation axis JC Joint restraint mechanism (drive torque adjustment member)
US familiar mechanism

Claims (26)

1. From the number of actuators (24, 25; 119, 120; 219; 330; 413), the number of joints (13, 14, 15; 113, 114, 115; 213, 214; 331, 332, 333; 424, 425, 426) A number of underactuated mechanism robot hands (8; 108; 300),
   Palm (11; 111; 311);
   A plurality of links (16, 17, 18; 116, 117, 118; 216, 217; 301, 302, 303, 304) whose roots are coupled to the palm (11; 111; 311) and are bendably coupled. 414, 417, 421) with at least two fingers (12, 12A; 112; 212; 312, 313, 314; 400);
   Provided on at least one of the fingers (12A; 112; 212; 312; 400), imparting torsional displacement to the link (17, 18), and the joint (114; 213; 331, 332; 424) ) Is performed by adjusting at least one of the driving torque adjustments required to drive the object (9), the finger (12, 12A; 112; 212; 312, 313, 314; 400) holds the grasped object (9). A robot hand (8; 108) characterized by having a conforming mechanism (US) that can be gripped so as to be wrapped.
2. Comprising three or more fingers (12, 12A);
   Each of the three or more fingers (12, 12A)
   Three or more links (16, 17, 18) including a first link (16), a second link (17), and a third link (18) arranged in order from the palm side toward the fingertip. )When,
   The first joint (13), the second link (17), and the first link (16) that flexibly connect the first link (16) and the palm side of the first link (16). 3 or more including a second joint (14) for flexibly connecting and a third joint (15) for flexibly connecting the third link (18) and the second link (17). Said joints (13, 14, 15),
   At least one link (16) of the first to third links (16, 17, 18) provided on at least one of the three or more fingers (12, 12A). Is constituted by two small link members (35, 36) connected to each other around the rotation axis (CL) so as to be capable of relative torsional displacement, thereby realizing the conforming mechanism (US). Item 8. The robot hand (8) according to item 1.
3. The familiar mechanism (US)
   3. A twist mechanism (38, 38A to C) for connecting the two small link members (35, 36) to each other around the rotation axis (CL) so as to be capable of relative torsional displacement. The robot hand (8) as described.
4. The twist mechanism (38, 38A to C)
   A shaft member (42, 42B) provided on one of the two small link members (35, 36);
   A bearing member (44) provided on the other of the two small link members (35, 36) and rotatably supporting the shaft member (42, 42B). The robot hand (8) as described.
5. The twist mechanism (38, 38A to C)
   A guide member (45, 45B, 47) is provided for guiding relative rotation of the two small link members (35, 36) accompanying rotation of the shaft member (42, 42B). Item 5. The robot hand (8) according to item 4.
6. The twist mechanism (38, 38A to C)
   Restricting members (45, 45B, 47) for limiting the amount of rotation of the two small link members (35, 36) in the relative rotational direction within a predetermined range as the shaft members (42, 42B) rotate. The robot hand (8) according to claim 4 or 5, characterized by comprising:
7. The twist mechanism (38, 38A to C)
   A return force applying member (46, 42) for applying a return force for displacing the two small link members (35, 36), which are displaced in the forward rotation direction with the rotation of the shaft members (42, 42B), in the reverse rotation direction. The robot hand (8) according to any one of claims 4 to 6, comprising 51, 52, 56).
8. The return force applying member (46, 51)
   A first spring member having one end fixed to one of the two small link members (35, 36) and the other end fixed to the other of the two small link members (35, 36) The robot hand (8) according to claim 7, wherein the robot hand (8) is (46, 51).
9. The return force applying member (52)
   The pair of permanent magnets (52) arranged opposite to each other in each of the two small link members (35, 36) so that the attractive force as the restoring force acts on each other. The robot hand (8) described in 1.
10. The return force applying member (56)
    Among the two small link members (35, 36), the two small link members (35, 36) are housed and arranged in one predetermined storage space, and the two small link members (35, 36) are rotated along with the rotation of the shaft member (42). The robot hand (8) according to claim 7, wherein the robot hand (8) is a rubber member (56) or a resin member that is pressed and compressed by a pressing member (55) fixed to the other.
11. The first link (16) is composed of the two small link members (35, 36),
    And,
    The palm (11);
    A first actuator (24) provided on the palm (11) for generating a first driving force for bending the first link (16);
    Of the two small link members (35, 36), the small link member (36) on the second link (17) side is provided to bend the second link (17) and the third link (18). A second actuator (25) for generating a second driving force for
    A second link drive transmission mechanism (30, 31) for transmitting the second driving force from the second actuator (25) to the second link (17);
    A third link drive transmission mechanism (30, 31, 32, 33, 34) for transmitting the second driving force from the second actuator (25) to the third link (18);
    The robot hand (8) according to any one of claims 4 to 10, characterized by comprising:
12. The second link drive transmission mechanism (30, 31)
    A gear mechanism (30, 31) for transmitting the second driving force to the second link (17) by gear coupling;
    The third link drive transmission mechanism (30, 31, 32, 33, 34)
    The third link is formed by a belt member (34) or a wire member that is stretched between a pulley (33) provided on the third link (18) and a pulley (32) provided on the second link (17). The robot hand (8) according to claim 11, further comprising a pulley mechanism (32, 33, 34) for transmitting the second driving force to (18).
13. The shaft member (42, 42B)
    The robot hand (8) according to claim 11 or 12, characterized in that it comprises an axial through hole (48) for allowing the cable member (49) to penetrate the second actuator (25).
14. The familiar mechanism (US)
    Torque transmission mechanisms (122, 123, 124; 222, 223, 224) that transmit the torque of the actuator (120; 219; 413) to two or more of the joints (114, 115; 213, 214; 424, 425). 401,700)
    In the gripping operation, the joint (114; 213; 424) is so driven that the joint (114; 213; 425) on the palm side is bent before the joint (115; 214; 424) on the fingertip side. The robot hand (108) according to claim 1, further comprising a drive torque adjusting member (127, 137; 227; 422, JC) for adjusting a drive torque required to drive the robot.
15. The torque transmission mechanism (122, 123, 124; 222, 223, 224)
    A drive pulley (122; 222) coupled to the palmar joint shaft (1141; 2131);
    A driven pulley (123; 223) connected to the joint shaft (1151; 2141) on the fingertip side;
    A belt (124; 224) stretched over the drive pulley (122; 222) and the driven pulley (123; 223),
    The drive torque adjusting member (127, 137; 227)
    In the gripping operation, the driving torque required to drive the palm joint (114; 213) is smaller than the driving torque required to drive the fingertip joint (115; 214). Thus, during the grip release operation, the driving torque necessary to drive the palm-side joint (114; 213) is the driving torque required to drive the fingertip-side joint (115; 214). 15. The robot hand according to claim 14, wherein the robot hand is a second spring member (127, 137; 227) that applies an auxiliary torque to the palm-side joint (114; 213) so as to be larger. 108).
16. The second spring member (127; 227)
    The robot hand (108) according to claim 15, wherein the robot hand (108) is a torsion spring (127; 227) provided around the joint axis (1141; 2131) on the palm side.
17. The second spring member (137) is
    The robot hand (108) according to claim 15, wherein the robot hand (108) is a tension spring (137) connected to wires (138A, 138B) provided around the joint axis (1141) on the palm side.
18. The finger (112; 212)
    16. A stopper (128, 129; 229) for restricting the posture of the link (117, 118; 217) on the fingertip side with respect to the link (116, 117; 216) on the palm side. The robot hand (108) according to any one of claims 17 to 17.
19. The stopper (129)
    A pin (129A) provided on the palm side link (117);
    The guide groove (129B) provided on the fingertip side link (118) and capable of restricting an operating range of the inserted pin (129A), according to claim 18, Robot hand (108).
20. The torque transmission mechanism (401)
    A sun gear (4102), a carrier (4104), and a ring gear (4106), one of the carrier (4104) and the ring gear (4106) being a palm-side joint shaft (407) and the other being a fingertip-side joint A planetary gear mechanism (401) coupled to a shaft (420);
    The drive torque adjusting member (422; JC)
    In the gripping operation, the fingertip is configured such that a driving torque required to drive the palm-side joint (425) is smaller than a driving torque required to drive the fingertip-side joint (424). The robot hand according to claim 14, wherein the robot hand is a joint restraining mechanism (422; JC) for restraining driving of the joint shaft (420) on the side.
21. The torque transmission mechanism (700)
    A wave generator (701), a flex spline (702), and a circular spline (703) are provided, one of the flex spline (702) and the circular spline (703) being a palm-side joint axis (407) and the other being a fingertip A wave gear mechanism (700) connected to the side joint shaft (420),
    The drive torque adjusting member (422; JC)
    In the gripping operation, the fingertip is configured such that a driving torque required to drive the palm-side joint (425) is smaller than a driving torque required to drive the fingertip-side joint (424). The robot hand according to claim 14, wherein the robot hand is a joint restraining mechanism (422; JC) for restraining driving of the joint shaft (420) on the side.
22. From the number of actuators (24, 25; 119, 120; 219; 330; 413), the number of joints (13, 14, 15; 113, 114, 115; 213, 214; 331, 332, 333; 424, 425, 426) A robot device (1) comprising a robot hand (8; 108; 300) having a large number of underdrive mechanisms and a controller (3) for controlling the robot hand (8; 108; 300),
    The robot hand (8; 108; 300)
    Palm (11; 111; 311);
    A plurality of links (16, 17, 18; 116, 117, 118; 216, 217; 301, 302, 303, 304) whose roots are coupled to the palm (11; 111; 311) and are bendably coupled. 414, 417, 421) with at least two fingers (12, 12A; 112; 212; 312, 313, 314; 400);
    Provided on at least one of the fingers (12A; 112; 212; 312; 400), imparting torsional displacement to the link (17, 18), and the joint (114; 213; 331, 332; 424) ) Is performed by adjusting at least one of the driving torque adjustments required to drive the object (9), the finger (12, 12A; 112; 212; 312, 313, 314; 400) holds the grasped object (9). A robot apparatus (1) having a conforming mechanism (US) that can be gripped so as to be wrapped.
23. The robot hand (8)
    Having three or more fingers (12, 12A);
    Each of the three or more fingers (12, 12A)
    Three or more links (16, 17, 18) including a first link (16), a second link (17), and a third link (18) arranged in order from the palm side toward the fingertip. )When,
    The first joint (13), the second link (17), and the first link (16) that flexibly connect the first link (16) and the palm side of the first link (16). 3 or more including a second joint (14) for flexibly connecting and a third joint (15) for flexibly connecting the third link (18) and the second link (17). Said joints (13, 14, 15),
    At least one link (16) of the first to third links (16, 17, 18) provided on at least one of the three or more fingers (12, 12A). Is constituted by two small link members (35, 36) connected to each other around the rotation axis (CL) so as to be capable of relative torsional displacement, thereby realizing the conforming mechanism (US). Item 23. The robot apparatus (1) according to Item 22.
24. The familiar mechanism (US)
    The twist mechanism (38, 38A to C) for connecting the two small link members (35, 36) to each other around the rotation axis (CL) so as to be capable of relative torsional displacement. The robot apparatus (1) described.
25. The robot hand (8)
    The first link (16) is constituted by the two small link members (35, 36),
    And,
    The palm (11);
    A first actuator (24) provided on the palm (11) for generating a first driving force for bending the first link (16);
    Of the two small link members (35, 36), the small link member (36) on the second link (17) side is provided to bend the second link (17) and the third link (18). A second actuator (25) for generating a second driving force for
    A second link drive transmission mechanism (30, 31) for transmitting the second driving force from the second actuator (25) to the second link (17);
    A third link drive transmission mechanism (30, 31, 32, 33, 34) for transmitting the second driving force from the second actuator (25) to the third link (18);
    The controller (3)
    25. The robot apparatus (1) according to claim 23 or 24, wherein driving of the first actuator (24) and the second actuator (25) is controlled.
26. The familiar mechanism (US)
    Torque transmission mechanisms (122, 123, 124; 222, 223, 224) that transmit the torque of the actuator (120; 219; 413) to two or more of the joints (114, 115; 213, 214; 424, 425). 401,700)
    In the gripping operation, the joint (114; 213; 424) is so driven that the joint (114; 213; 425) on the palm side is bent before the joint (115; 214; 424) on the fingertip side. The robot apparatus (1) according to claim 22, further comprising a driving torque adjusting member (127, 137; 227; 422, JC) for adjusting a driving torque necessary for driving the motor.

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